Integrating amplifier circuit using an apertured square loop magnetic core



Oct. 26, 1965 v F. SCHREIBER 3,

INTEGRATING AMPLIFIER CIRCUIT USING AN APERTURED SQUARE LOOP MAGNETIC CORE Flled July 10 1961 INVENTOR.

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United States Patent Office I 3,214,600 Patented Oct. 26, 1965 3 214 600 INTEGRATING AMPITIFiitR CIRCUIT USING AN APERTURED SQUARE LOOP MAGNETIC CORE Friedrich Schreiber, Munich-Solln, Germany, assignor to Siemens & Halske Aktiengesellschaft, Berlin and Munich, Germany, a German corporation v Filed July 10, 1961, Ser. No. 122,868 Claims priority, application Germany, July 8, 1960,

' 1 6 Claims. (a. 307- 88) This invention is concerned with an integrating amplifier circuit using a square'loop magnetic core with at least two apertures, constituting a switching member which has become known under the trade names Transfluxor or Magnistor. Such a switching member may also be described as a controllable six terminal device with storage properties. The transmission value between a pair of input terminals and a pair of output terminals can be selectively altered by impulse-wise triggering, the Transfluxor retaining thereby the adjusted transmission characteristics based upon its storage property.

The Transfluxor or Magnistor is a ring core made of a material with at least approximately rectangular hysteresis loop, having at least two apertures, whereby the flux which is operatively effective in one region of the ring core is subdivided into two partial fluxes. This region, which embraces one aperture, will be'herei'nafter referred to as initial aperture (controlled circuit). The device can be adjusted, by partial setting of the flux in the input circuit or in the control circuit, so that the inductivity and opposing inductivity, respectively, of the windings which are over this ap'erturelinked with the core, assume different values, whereby the values which have once been adjusted are retained by the action of the remanence of the magnet core.

In connection with such a device, there is recognized a basic distinction between two positions of magnetization, namely, the magnetization direction, for example, in clockwise direction of a ring shaped Transfluxor, is designated as blocking direction, while a magnetization in opposite direction, which generally must not occupy more than one-half of the cross-sectional areaof the device, is designated as adjusting or setting direction. Accordingly, as soon as the entire cross-sectional area of a Transfluxor is magnetized in the blocking direction, the Transfluxor' is blocked, that is, there is no magnetization possible about the output aperture, While the Transfluxor is adjusted more or less in the other direction, even with only partial magnetization of the cross sectional area, that is, there is a higher or lower magnetization possible about the output aperture, whereby the complete adjust ment is, as already mentioned, obtained, when half of the cross-sectional area had been magnetized in the adjusting or setting direction.

It may easily be seen, from the foregoing explanations, that such a device operates as an integrating amplifier, since a conditionthat has once been set or adjusted, and which corresponds to the time integral of the pulses used for the setting, remains preserved for a desired length of time, whereby the setting or adjustment is in appropriate manner supplemented by a successive pulse.

The various objects and features of the invention will appear from the description which is rendered below with reference to the accompanying drawing.

FIG. 1 shows a customary Transfiuxor T in a known circuit; I H

FIG. 2 shows a device according to the invention;

FIG. 3 represents an impulse diagram as an aid to ex-' plain conditions in a partially adjusted Tran'sfluxor; and

FIG. 4 shows an embodiment of the invention in which the impulse source is electrically separated from the load circuit. j V

The customary Transfluxor T, shown in FIG. 1 in a known circuit, illustrates the problemsinvolved. The Transfluxor T has a relatively large input aperture and a smaller output aperture. The input aperture is linked with the input winding N1. Upon the leg lying at the right of the output aperture are provided two power transmission windings N2 and N3. Over the winding N3 is supplied an alternating current which is by the inductive coupling over the winding N2 conducted to the load resistor Ra; The current thus supplied is limited by aresistor R3. H w p 7 When a voltage pulse of given polarity is impressed on the input winding N1, the Transfluxor is brought wholly or partially into a defihedremanence position which differs from the original remanence position. The coupling between the windings N2 and N3 is thereby changed, so that the current conducted to the load resistor Ra, that is, the power conducted to this resistor, is proportional to the time integral over the voltage conducted to the input winding.

Since the adjusting flux is proportional to u di, wherein u; is the input voltage at the Winding N1, it may be de-' rived mathematically, by applying the induction rule, that the output power P2 is proportional to the adjusting flux P 2ju dt This similarity relation is true for the average value of the output current. The output power is limited by the fact that an alternating current is conducted to the winding N3, such cur-rent acting on the one hand in blocking direction and on the other hand in the adjusting direction of the magnetic field. This introduce's the danger that the half waves which lie in the adjusting direction, support the field produced by the input voltage u' thereby producing an additional adjustment which does not any more correspond to the input voltage. For this reason, at least one of the half waves of the alternating current supplied over the winding N3, must be limited as toarnplitude so that erroneous adjustment is reliably prevented.

The invention is concerned with an amplifier circuit including a Transfluxor or Magnistor in which the output power can be very much increased; t

As compared with known Transiluxor or Magnistor circuits' which operate as integrating amplifiers, the circuit according to the present invention provides't for taking off the output powerover two windings" arranged diam etrically upon the legs of the p'owervtransmiss'ion or output aperture, such windings becoming alternatively effective with each ha'lf wave of a feed current, preferably over a rectifier circuit, whereby the: polarity conducted to the individual windings, and the sense of winding direction thereof, are mutually matched so that there is produced a resultant field extending always in the direction of the flux which is operative to block the Transfluxor. I p p p In the circuit according to the invention, the output power is accordingly not conducted to the output aperture over one leg thereof, as in the known circuits, but the alternating current power which is conducted to the load, preferably over a rectifier circuit, is separated according to its polarities, and the two possible polarities are conducted over the two legs of the Transfluxor, whereby the polarity and the sense of winding direction are for each leg selected so that only one flux change is always produced in the direction of the fluxes which act to block the Transfluxor. This avoids reliably the danger that the Transfluxor may be additionally set or adjusted by individual half waves of the alternating current conducted to the load.

In a particularly advantageous embodiment of the amplifier circuit according to the invention, two phase shifted pulse sequences of unipolar pulses are as alternating control current conducted to the load over the two legs of the output aperture, whereby the two pulse sequences are preferably phase shifted by 180. Maximum power can be conducted to the load when the frequency of the carrier generator is tuned so that the reverse magnetization about the output aperture is in the fully adjusted condition of the Transfluxor just completed at the end of a half wave.

Details of the invention and advantages thereof will now be discussed with reference to FIGS. 2 to 4.

FIG. 2 shows the square loop magnetic core of a Transfluxor, which is for ready comprehension conveniently represented in special rectangular configuration. The Transfluxor corresponds as to the number of windings and its broadly basic operation to the Transfluxor explained with reference to FIG. 1. The voltage a which is to be integrated is again supplied over a winding N1. With a positive sign, this voltage effects the adjustment of the Transfluxor which is initially blocked. There are moreover provided windings N4 and N5. These windings are disposed diametrically each upon a leg of the power transmission or output aperture, thus being respectively linked with different regions of the cross-sectional iron area of the Transfluxor core. These windings are circuited in series with the load Ra.

In accordance with the invention, the windings N4 and N5 are supplied with timing pulses of the identical frequency, which are mutually phase shifted. These two phases of the timing pulse are obtained from separate outputs of an impulse source I (carrier generator). The polarity of the pulses or of the windings N4, N5, respectively, .is such that the pulses support a flux extending in blocking direction, that is, in the illustrated example, a downwardly directed flux extending in the direction of the arrows. The two windings are combined at the output side. In the feed-in lines extending to the respective windings are inserted diodes D1 and D2, such diodes preventing current flow over the windings which would support the adjustment of the Transfluxor. The addition of the pulses of both phases produces in the load Ra practically a pulse-length modulated current, the mean value of which as to time, is determined by the inductive impedance of the windings N4 and N5. As previously pointed out, the inductive impedance is in turn dependent upon the magnitude of the adjusted flux.

Since the inductive action of the respective windings N4, N5 is present during each half wave, there will flow, with fully adjusted Transfluxor, a relatively low magnetizing current which can be compensated if required. However, maximum current will flow with fully blocked Transfluxor, since the two windings act in such case as simple air coils, thus being practically ineffective.

The conditions for a partially adjusted Transfluxor will now be explained with reference to the impulse diagram shown in FIG. 3.

Lines (a) and (b) in FIG. 3 show individual impulse voltages delivered by the impulse generator I included in FIG. 2. Depending upon the degree of adjustment of the Transfluxor, the magnetic circuit extending about the power transmitter or output aperture is by each impulse flowing through the windings N4, N5 (FIG. 2) more or less rapidly oppositely magnetized to saturation condition, minimum current flowing thereby initially and thereafter maximum current, for the duration of a feed impulse extended from the impulse source. The ratio of duration in time of the minimum and maximum current depends upon the degree of adjustment so that the mean value as to time, of the current depends linearly on the degree of the adjustment, that is, upon the time integral of the input voltage (see also line (c) in FIG. 3). Accordingly, a mean value will result as a load current, which corresponds to this ratio. This current in the load therefore depends upon the time integral of the input voltage.

The integrating amplifier, explained with reference to FIG. 2, thus operates in stable and continuous manner, with the advantage, as compared with known integrating amplifiers constructed of Transfluxors, of producing a higher output power.

FIG. 4 shows an example of an embodiment of the invention, in which the circuit supplied from the impulse source is electrically separated from the output circuit which feeds into the load. Two windings are for this purpose provided on each leg of the output aperture, namely, one primary winding which is supplied from the impulse source I, and one secondary winding which feeds into the load Ra. The diodes D3 and D4 are in this case provided in the secondary circuit for decoupling the two secondary windings.

An embodiment according to FIG. 4 is compared with an embodiment according to FIG. 2 less efficient because part of the power is consumed in the resistor R3 which would in a substitution diagram be in series with the load resistor Ra. The resistor R3 is however required for limiting the current taken from the generator I.

Changes may be made within the scope and spirit of the appended claims which define what is believed to be new and desired to have protected by Letters Patent.

I claim:

1. An integrating amplifier circuit constructed with the use of a Transfluxor which is adjusted or blocked by the effect of the input voltage which is to be integrated, and over the output aperture of which is obtained the output power for connection to a load, comprising two windings, over which the output power is obtained, said windings being disposed diametrically upon the legs of the output aperture, circuit means for alternately conducting to said windings a half wave of an alternating feed current produced by an impulse source, the polarity of said feed current conducted to the respective windings being matched to the sense of direction of the windings so as to cause the field induced over such windings to act in the direction of the flux which is operative to block the Transfluxor.

2. An integrating amplifier circuit according to claim 1, wherein said circuit means comprises rectifier means.

3. An integrating amplifier circuit according to claim 1, wherein said alternating feed current is a current composed of two mutually phase shifted pulse sequences of identical frequency, the pulses of said sequences having a duration which corresponds to the maximum time of the opposing magnetization occurring at the output aperture, and means for extending the respective pulse sequences each over one leg of the output aperture to the load.

4. An integrating amplifier circuit according to claim 1, wherein said alternating feed current is a current composed of two pulse sequences of identical frequency but with the pulses thereof phase shifted by the pulses of said sequences having a duration which corresponds to the maximum time of the opposing magnetization occurring at the output aperture, and means for extending the respective pulse sequences each over one leg of the output aperture to the load.

5. An integrating amplifier circuit according to claim 1, comprising, for the separation of the feed current source and the load circuit, a primary winding di-sposed upon each leg of the output aperture, means for connecting said primary windings with the impulse source, a secondary winding likewise disposed upon each leg of the output aperture, and a circuit for feeding the load from said secondary windings, said last named circuit containing rectifier means for decoupling said secondary windings.

6. An integrating amplifier circuit according to claim 3, comprising, for the separation of the feed current source and the load circuit, a primary winding disposed upon each leg of the output aperture, means for connecting said pri- 6 mary windings with the impulse source, a secondary Winding likewise disposed upon each leg of the output aperture, and a circuit for feeding the load from said secondary windings, said last named circuit containing rectifier means for-decoupling said secondary windings.

IRVING L. SRAGOW, Primary Examiner. 

1. AN INTEGRATING AMPLIFIER CIRCUIT CONSTRUCTED WITH THE USE OF A TRANSFLUXOR WHICH IS ADJUSTED OR BLOCKED BY THE EFFECT OF THE INPUT VOLTAGE WHICH IS TO BE INTEGRATED, AND OVER THE OUTPUT APERTURE OF WHICH IS OBTAINED THE OUTPUT POWER FOR CONNECTION TO A LOAD, COMPRISING TWO WINDINGS, OVER WHICH THE OUTPUT POWER IS OBTAINED, SAID WINDINGS, BEING DISPOSED DIAMETRICALLY UPON THE LEGS OF THE OUTPUT APERTURE, CIRCUIT MEANS FOR ALTERNATELY CONDUCTING TO SAID WINDINGS A HALF WAVE OF AN ALTERNATING FEED CURRENT PRODUCED BY AN IMPULSE SOURCE, THE POLARITY OF SAID FEED CURRENT CONDUCTED TO THE RESPECTIVE WINDINGS BEING MATCHED TO THE SENSE OF DIRECTION OF THE WINDINGS SO AS TO CAUSE THE FIELD INCUDED OVER SUCH WINDINGS TO ACT IN THE DIRECTION OF THE FLUX WHICH IS OPERATIVE TO BLOCK THE TRANSFLUXOR. 